FABRICATION AND PROPERTIES OF HOT-PRESSED URANIUM MONONITRIDE

Technical Report · Thu May 30 04:00:00 EDT 1963

DOI:https://doi.org/10.2172/4674236· OSTI ID:4674236

Speidel, E O; Keller, D L

Dense UN specimens for property tests were fabricated primarily by an isostatic hot-pressing technique in which consolidated powder sealed in a refractory metal container was subjected to a 10,000-psi external gas pressure at 1480 to 1540 deg C for 3 to 4 hr. The thermal conductivity of uranium mononitride increased from 0.04 cal/(cm)(sec)( deg C) at 200 deg C to 0.06 cal/ (sec)(cm/sup 2/)( deg C) at 1000 deg C, which by an integrated thermal- conductivity criterion, makes it some eight times more effective than UO/sub 2/ in transferring heat. Thermal-expansion coefficients of 9.0 x 10/sup -6/ per deg C and 9.9 x 10/sup -6/per deg C over the ranges 20 to 800 deg C and 20 to 1600 deg C, respectively, were measured. UN retained about 80% of its room- temperature hardness at 1100 deg C. Above this temperature, the hardness dropped rapidly with increasing temperature. The specific heat is cal per g mole can be conveniently described by the equition C = 13.32 + 1.19 x 10/sup -3/ T --2.10 x 10/sup 5/ T/sup -2/ over the range 273 to 142 3 deg K. Electrical conductivity dropped with increasing temperature a metallic characteristic. Anomalies were noted in attempts to measure the hydiogen solubility and the resistance to water corrosion. UN is apparently not attacked by NaK within 1500 hr at temperatures up to 480 deg C. (auth)

• Research Organization: Battelle Memorial Inst., Columbus, Ohio
• DOE Contract Number: W-7405-ENG-92
• NSA Number: NSA-17-030906
• OSTI ID: 4674236
• Report Number(s): BMI-1633; EURAEC-706
• Country of Publication: United States
• Language: English

Related Subjects

CHEMICAL REACTIONS
CORROSION
ELECTRIC CONDUCTIVITY
EQUATIONS
EXPANSION
HARDNESS
HEAT TRANSFER
HIGH TEMPERATURE
HOT WORKING
HYDROGEN
METALS
METALS, CERAMICS, AND OTHER MATERIALS
POTASSIUM
POWDERS
PRESSURE
SINTERING
SODIUM
SOLUBILITY
SPECIFIC HEAT
TEMPERATURE
THERMAL CONDUCTIVITY
URANIUM DIOXIDE
URANIUM NITRIDES
VESSELS
WATER